Transcript Description

4-1
Chapter
4
Hardware: The CPU &
Storage
4.1 Microchips, Miniaturization, & Mobility
4.2 The System Unit: The Basics
4.3 More on the System Unit
4.4 Secondary Storage
4.5 Future Developments in Processing &
Storage
McGraw-Hill/Irwin
© 2007 The McGraw-Hill Companies, Inc. All rights reserved.
Microchips, Miniaturization, &
Mobility
Vacuum Tubes vs. Transistors
 Vacuum
tubes were the original logic gates of computers
 They looked like light bulbs, were hot, and burned out
like them too
 The original transistors were 1/100th the size of vacuum
tubes (less power, faster, more reliable too)
Transistors vs. Integrated Circuits
 Compare
1955’s 45 lb “portable” color TV to today’s 7 oz
Casio 2.3 inch color TV
 One integrated circuit contains thousands of transistors
4-3
Microchips, Miniaturization, &
Mobility
Semiconductor
A material
whose electrical properties are
intermediate between a good conductor and a
nonconductor of electricity
Perfect substrate to overlay complex circuits on
Microchips are made from semiconductors
Contain millions of microminiature integrated
circuits
4-4
Microchips, Miniaturization, &
Mobility
Microprocessor
 The
miniaturized circuitry of an entire computer
processor on a single chip
 Contains the CPU, which processes data
Microcontroller or Embedded Computer
 A microprocessor
that was modified for use in a machine
that isn’t a computer
4-5
The System Unit: The Basics
 Binary System: the basic unit of computing
 Uses
just two numbers: 0 and 1
 All data and program instructions in the computer are
represented as binary
 Bit: each 0 or 1 is a bit
 Byte: a group of 8 bits
 Kilobyte: ~1,000 (1,024) bytes
 Megabyte: ~1 Million (1,048,576) bytes
 Gigabyte: ~1 Billion (1,073,741,824) bytes
 Terabyte: ~ 1 Trillion (1,009,511,627,576) bytes
 Petabyte: ~ 1 quadrillion bytes
 Exabyte: ~ 1 quintillion bytes
 All the printed material in the world is ~ 5 exabytes
4-6
The System Unit: The Basics
Binary coding schemes assign a unique binary code to
each letter
 EBCDIC
 Requires
8 bits per character
 Used for IBM mainframes
 ASCII
 Requires
7 or 8 bits per character, depending on the version
 8 bit Extended ASCII provides 256 characters
 Used for PCs, Unix hosts, Macs
 Unicode
 Requires
16 bits per character
 Handles 65,536 characters
4-7
The System Unit: The Basics
Error Checking: Parity Bits
 Used
in modems & communications to verify correctness
 One check bit is added to 7 bit byte
 The check bit is defined as either odd or even
 For odd parity, if the data sent is correct, the parity bit
plus the first 7 data bits is an odd number
 For even parity, if the data sent is correct, the parity bit
plus the first 7 data bits is an even number
Discussion Question: If the 7 data bits are 1101011, and the modem is
sending odd parity, what should the parity bit be set to?
Answer: Since the data bits add up to 5, an odd number, the parity bit
will be 0.
4-8
The System Unit: The Basics
Machine Language
 A binary-type
programming language built into the CPU
that is run directly by the computer
 Each CPU type has its own machine language
Language Translators
 System
programs convert the programming instructions
for you into machine language
4-9
The System Unit: The Basics
4-10
The System Unit: The Basics
Computer Terms
 Names
1. Bay
2.
3.
4.
5.
6.
7.
8.
 Definitions
1.
2.
Power Supply
Surge Protector 3.
Voltage
Regulator
UPS
4.
5.
6.
Motherboard
Microprocessor 7.
8.
Chipset
Shell or opening used for the installation of electrical
equipment.
This converts AC to DC to run the computer.
Protects the computer from being damaged by power spikes.
Plug your computer into one.
Protects a computer against brownouts or low power
conditions that happen a lot in summer.
Uninterruptible Power Supply. Battery-operated device that
provides power for a time when there is a blackout.
The main system board of the computer.
The miniaturized circuitry of a computer processor.
Groups of interconnected chips on the motherboard that
control information flow between the microprocessor and
other system components connected to the motherboard.
4-11
The System Unit: The Basics
The CPU
 Older

CPUs processing speeds are in MegaHertz
1 MHz = 1 Million ticks per second
 Current

CPUs processing speeds are in GigaHertz
1 GHz = 1 Billion ticks per second
 The
faster a CPU runs, the more power it consumes, and
the more heat it generates
4-12
The System Unit: The Basics
The CPU Continued
Mainframe
and minicomputer speed is measured in
MIPS
 MIPS
stands for millions of instructions per second
 Workstations perform at 100 MIPS or more
 Mainframes perform at 200 – 1,200 MIPS
Supercomputer
processing speed is measured in
flops
 Flops
stands for floating point operations per second
 IBM’s Blue Gene/L cranks out 70.72 teraflops (tera = trillion)
per second
4-13
More on the System Unit
Parts of the CPU
Definition
1.
Name
Word size
2.
Control unit
2. The part of the CPU that deciphers
instructions and carries them out
3.
3. The ALU performs mathematical and logical
operations and controls the speed of them
4.
Arithmetic
Logic Unit
Registers
5.
Buses
5. Electrical data roadways used to transmit bits
within the CPU and between CPU and other
motherboard components
1. The number of bits the processor can
process at any one time
4. High-speed storage areas that temporarily
store data during processing
4-14
More on the System Unit
How Memory Works
1.
Memory Chip
RAM
1.
2.
ROM
2.
3.
CMOS
3.
4.
Flash
4.
Explanation
Random Access Memory chips are volatile and hold:
a.
Software instructions
b.
Data before & after the CPU processes it
Read only memory
a.
Cannot be written on or erased without special
equipment
b.
Are loaded at factory with fixed start-up
instructions
Complementary Metal Oxide Semiconductor
a.
Powered by a battery
b.
Contains time, date, calendar, boot password
Nonvolatile memory that can be erased and
reprogrammed more than once
a.
Doesn’t require a battery
b.
Used in newer PCs for BIOS instructions
4-15
More on the System Unit
Types of RAM
RAM Types
1. DRAM
2.
SDRAM
3.
SRAM
Explanation
1. Dynamic RAM must be constantly refreshed by
the CPU or it loses its contents
Synchronous Dynamic RAM is synchronized by
the system clock and is much faster than DRAM
3. Static RAM is faster than DRAM and retains its
contents without having to be refreshed by CPU
2.
Double-data rate synchronous dynamic RAM
5. Single Inline Memory Module has RAM chips on
only one side
4.
4.
6.
FPM is fast page mode type
b.
EDO is extended data output; is faster than FPM
6. Dual Inline Memory Module has chips on both sides
DDR-SDRAM
5. SIMM
a.
DIMM
4-16
More on the System Unit
Speeding up Processing
The CPU works much faster than RAM
 So
it could sit there waiting for information
 Cache temporarily stores instructions and data that the
processor uses frequently to speed up processing
 Level
1 cache is part of the microprocessor
Holds 8 to 256 kb
 Faster than Level 2 cache

 Level

Holds 64 kb to 2 Mb
 Level

2 cache is SRAM external cache
3 cache is on the motherboard
Comes on very high-end computers
4-17
More on the System Unit
Speeding up Processing
Method
1.
Interleaving
2.
Bursting
3.
Pipelining
Superscalar
Architecture
5. Hyperthreading
1.
2.
3.
4.
4.
5.
Description
CPU alternates communications between
two or more memory banks
CPU grabs a block of data from memory
instead of retrieving one piece at a time
CPU doesn’t wait for one instruction to
complete before fetching its next instruction
The computer can execute more than one
instruction per clock cycle
A technique used in superscalar architecture
in which the OS treats the microprocessor as
though it is two microprocessors
4-18
More on the System Unit
Ports
Port Type
1.
Serial Port
2.
Parallel Port
3.
SCSI Port
4.
USB Port
Description
Used to transmit slow data over long distances
a. Sends data sequentially, one bit at a time
b. Used to connect keyboard, mouse,
monitors, dial-up modems
2. For transmitting fast data over short distances
a. Transmits 8 bytes simultaneously
b. Connects printers, external disks, backups
3. Small Computer System Interface
a. Connects up to 7 devices in a daisy chain
b. Transmits data 32 bits at a time
4. Universal Serial Bus can theoretically connect
up to 127 peripheral devices in a daisy chain
1.
4-19
More on the System Unit
USB
Goals
 Be
low-cost
 Be able to connect lots of devices
 Be hot swappable
 People
hate rebooting because it takes time
 Hot swapping means a device can be
connected/disconnected without rebooting
 Permit
plug and play
 Devices
are automatically configured when they are
installed – no need to download new drivers
4-20
More on the System Unit
USB Continued
Standards
1.1 – the original standard
 USB 2.0 – the current standard for new PCs
 USB On The Go (OTG) – currently under development
 USB
Connectors
A –
in USB Type 1.1 and 2.0
 B – in USB Type 1.1 and 2.0
 Mini B – in USB Type 2.0
 Mini A – in USB OTG used for smaller peripherals like
cellphones
4-21
More on the System Unit
Specialized Expansion Ports
Port Type
1.
FireWire
Description
1.
Intended for devices working with lots of data
a.
2.
MIDI
b.
2.
Musical Instrument Digital Interface
a.
3.
IrDA
4.
Bluetooth
b.
Infrared Data Association: Infrared ports used to
make a cableless connection
4. Uses short-range radio waves that transmit up to 30
ft
b.
Ethernet
Connects musical instruments
Used in creating, recording, editing, performing music
3.
a.
5.
Used for camcorders, DVD players, TVs
Handles up to 400 megabits per second
5.
Connects computers to printers, keyboards, headsets,
even refrigerators
Named after King Harald Bluetooth, son of Gorm, who
united the Norway and Denmark. Ruled 910-940 A.D.
The standard for linking all devices in a Local Area
Network
4-22
More on the System Unit
Expansion Cards
4-23
More on the System Unit
Expansion Buses
Bus
1. PCI bus
2. AGP Bus
Description
1. Peripheral Component Interconnect
a. For high-speed connections
b. 32 or 64 bits wide
c. Typically used for sound cards, modems,
high-speed network cards
2. Accelerated Graphics Port
a. Twice the speed of PCI bus
b. For Video and 3-D graphics cards
4-24
Secondary Storage
Storage Types
1.
Floppy and Zip disks
Descriptions
1.
Removable disks.
Floppies store 1.44 MB
b.
Zip disks store 100, 250, or 750 MB
Made from thin rigid metal covered with
magnetizable substrate. Most disks have 2 or
more platters
Removable CDs and DVDs
Thin plastic tape coated with magnetizable
substance
Like a credit card, but contains a microprocessor
and memory chips
Nonvolatile memory – no moving parts
Lets you store data on an online vendor’s server
a.
Hard disks
2.
Optical disks
4. Magnetic tape
3.
2.
3.
Smart Cards
6. Flash memory
7. Online secondary
storage
5.
4.
5.
6.
7.
4-25
Secondary Storage
Floppies and Zip Disks
 Floppies
Flat piece of mylar plastic
inside a 3.5” plastic case
 Store about 1.44 MB
 Have a write-protect notch
 Data is recorded in tracks:
concentric recording bands
 Formatting breaks the tracks
into small wedge-shaped
sectors
 Read/Write head transfers
data between the computer
and disk
 Floppies DO wear out!
 Zip Disks
Disks with a high-quality
magnetic coating
 Store 100, 250, or 750 MB
 Require a Zip drive; won’t
work on floppy drives
 Used to store larger files than
floppies can hold
 Zip disks wear out too!


4-26
Secondary Storage
Hard Disks
Thin, rigid metal, glass, or ceramic platters covered with
a substance that allows data to be held in the form of
magnetized spots
 The
more platters there are, the higher the drive capacity
 Store data in tracks, sectors, and clusters
 Formatting creates a file allocation table that maps files to
clusters or inodes
 Typical
file systems are VFAT & NTFS for Windows, HFS and
ext2 for Unix
 Drive
heads ride on .000001” cushion of air, and can crash!
 Important data should always be backed up!
4-27
Secondary Storage
Hard Disks
Hard Disk Types:
Hard Disks – a freestanding disk drive
 Removable Hard Disk – inserted into a cartridge drive on
the PC
 External
Hard Disk Controllers
 EIDE
– Enhanced Integrated Drive Electronics
 Supports
up to 4 disks at 137 GB per disk
 Marketed as SATA, Fast ATA, Ultra ATA, ATA-2, ATA/100
– Faster than EIDE controllers
 Fibre Channel – used in large servers – faster and
costlier than SCSI
4-28
 SCSI
Secondary Storage
Optical Disks
CDs and DVDs are Optical disks
Data is written and read using lasers, not a disk head
 CD-ROM
is Compact Disk Read-Only Memory
 CD-R
is used for recording only once
 CD-RW is an erasable optical disk that can both record and
erase data over and over again
 DVD
is a CD-style disk with extremely high capacity
 Stores
4.7 or more GB
 DVD-R is used for recording only once
 DVD-RW, DVD-RAM, DVD+RW are reusable DVDs
4-29
Secondary Storage
Magnetic Tape
Thin plastic tape coated with a substance that can be
magnetized
 Store
200 GB and higher
 Used in the form of tape cartridges
 Still popular for large backups because of their large data
capacity
 But don’t get it near a magnet as that will erase it!
4-30
Secondary Storage
Smart Cards
 Resembles a credit card, but contains a microprocessor and
memory chips
 Holds more information than standard magnetic-strip credit
cards; 8 – 40 MB of data
 UltraCard
Uses a magnetic shim that draws out of the card to be read, then
retracts into the drive
 Provides 2 GB of storage

 Contact
smart cards
Must be swiped through card readers
 Can wear out from use

 Contactless

smart cards
Read when held in front of a low-powered laser
4-31
Secondary Storage
Flash Memory
Nonvolatile memory with no moving parts
 But
the electronics can wear out
 Available as
 Flash

Insert these into a flash port of a camera, handheld PC,
smartphone
 Flash

memory cards
memory sticks
A form of flash memory that plugs into a memory stick port
 Flash
memory drives
A finger-sized module of flash memory
 Plugs into the USB port of most PCs and Macintoshes

4-32
Secondary Storage
Online Secondary Storage
Allows you to use the internet to back up your data
 Sign
up with a vendor and receive access to software
that allows you to upload your data to that company’s
server
 Files should be encrypted to maintain security
 Use only for vital files that require immediate availability
 Use tape, removable hard disk cartridges, zip disks,
optical storage or tape for normal backup
4-33
Future Developments in
Processing & Storage
 Moore’s Law
 Gordon
Moore predicted the number of transistors on a silicon
chip will double every 18 months
 It has held up since the 1960s!
4-34
Future Developments in
Processing & Storage
Description of Processing Technology
New Technology
1.
M-RAM
1.
2.
OUM
2.
3.
Nanotechnology
3.
Optical Computing
5. DNA Computing
6. Quantum
Computing
4.
4.
5.
6.
Magnetic RAM uses miniscule magnets
rather than electrical charges
Ovonic Multiplied Memory stores bits by
generating different levels of low and high
resistance on a glossy material
Tiny machines work at a molecular level to
make nanocircuits
Uses lasers and light, not electricity
Uses strands of synthetic DNA to store data
Based on quantum mechanics and stores
information using particle states
4-35
Future Developments in
Processing & Storage
New Technology
1. Higher-density disks
Description of Storage Technology
1.
Magnetic disk drives currently hold 100
GB of data
Blank CDs are replacing floppy disks
since they hold 650MB and cost < $1
each
b.
DVD disks hold up to 4.7 GB of data
currently
c.
Perpendicular recording technology
allows 25% - 100% more data to be
stored on the same disk
2. Polymer memory creates chips that store
data on plastics
a.
Nonvolatile memory
b.
Data is stored based on polymer’s
electrical resistance
a.
2. Molecular
electronics
4-36